linux,shell中if else if的写法,if elif
最新回答
过期关系
2024-10-01 09:22:25
在编写shell脚本时，遇到需要对多个参数进行判断的情况，如:
#!/bin/bash
if [[ $1 = 'tomcat' ]]; then
echo "Input is tomcat"
elif [[ $1 = 'redis' ]] || [[ $1 = 'zookeeper' ]]; then
echo "Input is $1"
else
echo "Input Is Error."
fi
然而，初次尝试时，我们可能会误用为'else if'，导致脚本执行出错。如在测试脚本中：
bash
[oracle@standby ~]$ ./ts01.sh zookeeper
./ts01.sh: line 12: syntax error: unexpected end of file
问题在于，正确的写法是'elif'，而非'else if'。修正后的脚本如下：
bash
#!/bin/bash
if [[ $1 = 'tomcat' ]]; then
echo "Input is tomcat"
elif [[ $1 = 'redis' ]] || [[ $1 = 'zookeeper' ]]; then
echo "Input is $1"
else
echo "Input Is Error."
fi
重新执行修正后的脚本，我们得到预期结果：
[oracle@standby ~]$ ./ts01.sh zookeeper
Input is zookeeper
[oracle@standby ~]$ ./ts01.sh tomcat
Input is tomcat
[oracle@standby ~]$ ./ts01.sh redis
Input is redis
[oracle@standby ~]$ ./ts01.sh mysql
Input Is Error.
总结，shell脚本中处理多个条件的正确语法是使用if-elif-else结构，确保每个elif后面紧跟一个条件判断，而else则在所有条件都不满足时执行。
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